package com.mall.cart.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.mall.cart.feign.ProductFeignService;
import com.mall.cart.interceptor.CartInterceptor;
import com.mall.cart.service.CartService;
import com.mall.cart.vo.Cart;
import com.mall.cart.vo.CartItem;
import com.mall.cart.vo.SkuInfoVo;
import com.mall.cart.vo.UserInfoTo;
import com.mall.common.utils.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import java.math.BigDecimal;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.stream.Collectors;

@Slf4j
@Service
public class CartServiceImpl implements CartService {

    @Autowired
    StringRedisTemplate redisTemplate;

    @Autowired
    ProductFeignService productFeignService;

    @Autowired
    ThreadPoolExecutor executor;

    private final String CART_PREFIX = "gulimall:cart:";

    @Override
    public CartItem addToCart(long skuId, Integer num) throws ExecutionException, InterruptedException {
        BoundHashOperations<String, Object, Object> cartOps = getCartOps();
        String res = (String) cartOps.get(skuId + "");
        if(StringUtils.isEmpty(res)){
            CartItem cartItem = new CartItem();
            // 购物车无此商品

            // 2、添加新商品到购物车

            // 1、远程查询当前要添加的商品的信息
            CompletableFuture<Void> getSkuInfoTask = CompletableFuture.runAsync(() -> {
                R skuInfo = productFeignService.getSkuInfo(skuId);
                SkuInfoVo data = skuInfo.getData("skuInfo", new TypeReference<SkuInfoVo>() {
                });
                cartItem.setCheck(true);
                cartItem.setCount(num);
                cartItem.setImage(data.getSkuDefaultImg());
                cartItem.setTitle(data.getSkuTitle());
                cartItem.setSkuId(skuId);
                cartItem.setPrice(data.getPrice());
            },executor);

            // 3、远程查询sku的组合信息
            CompletableFuture<Void> getSkuSaleAttrValues = CompletableFuture.runAsync(() -> {
                List<String> skuSaleAttrValues = productFeignService.getSkuSaleAttrValues(skuId);
                cartItem.setSkuAttr(skuSaleAttrValues);
            }, executor);

            CompletableFuture.allOf(getSkuInfoTask,getSkuSaleAttrValues).get();
            String s = JSON.toJSONString(cartItem);
            cartOps.put(skuId + "",s);
            return cartItem;
        }
        else{
            // 购物车有此商品，修改数量
            CartItem cartItem = JSON.parseObject(res, CartItem.class);
            cartItem.setCount(cartItem.getCount() + num);

            cartOps.put(skuId + "",JSON.toJSONString(cartItem));
            return cartItem;
        }
    }

    @Override
    public CartItem getCartItem(Long skuId) {
        BoundHashOperations<String, Object, Object> cartOps = getCartOps();
        String str = (String) cartOps.get(skuId + "");
        CartItem cartItem = JSON.parseObject(str, CartItem.class);
        return cartItem;
    }

    @Override
    public Cart getCart() throws ExecutionException, InterruptedException {
        Cart cart = new Cart();
        UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();
        String cartKey = "";
        if (userInfoTo.getUserId() != null) {
            // 1、登录
            cartKey = CART_PREFIX + userInfoTo.getUserId();
            // 2、如果临时购物车的数据还没有进行合并[合并购物车]
            String tempCartKey = CART_PREFIX + userInfoTo.getUserKey();
            List<CartItem> tempCartItems = getCartItems(tempCartKey);
            if(tempCartItems != null){
                // 临时购物车有数据，需要合并
                for (CartItem item : tempCartItems) {
                    addToCart(item.getSkuId(),item.getCount());
                }
                // 清楚临时购物车的数据
                clearCart(tempCartKey);
            }

            // 3、获取登录后的购物车数据【包含合并过来的购物车数据，和非登录后的购物车的数据】
            List<CartItem> cartItems = getCartItems(cartKey);
            cart.setItems(cartItems);
        } else {
            // 2、没登录
            cartKey = CART_PREFIX + userInfoTo.getUserKey();
            // 获取临时购物车的所有购物项
            List<CartItem> cartItem = getCartItems(cartKey);
            cart.setItems(cartItem);

        }
        return cart;
    }

    /**
     * 获取到我们要操作的购物车
     * @return
     */
    private BoundHashOperations<String, Object, Object> getCartOps() {
        UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();
        String cartKey = "";
        if (userInfoTo.getUserId() != null) {
            cartKey = CART_PREFIX + userInfoTo.getUserId();
        } else {
            cartKey = CART_PREFIX + userInfoTo.getUserKey();
        }
//        redisTemplate.opsForHash().get(cartKey,"1");
        BoundHashOperations<String, Object, Object> operations = redisTemplate.boundHashOps(cartKey);
        return operations;
    }

    private List<CartItem> getCartItems(String cartKey){
        BoundHashOperations<String, Object, Object> hashOps = redisTemplate.boundHashOps(cartKey);
        List<Object> values = hashOps.values();
        if(values != null){
            List<CartItem> collect = values.stream().map(obj -> {
                String str = (String) obj;
                CartItem cartItem = JSON.parseObject(str, CartItem.class);
                return cartItem;
            }).collect(Collectors.toList());
            return collect;
        }
        return null;
    }

    @Override
    public void clearCart(String cartKey){
        redisTemplate.delete(cartKey);
    }

    @Override
    public void checkItem(Long skuId, Integer check) {
        BoundHashOperations<String, Object, Object> cartOps = getCartOps();
        CartItem cartItem = getCartItem(skuId);
        cartItem.setCheck(check == 1);
        String s = JSON.toJSONString(cartItem);
        cartOps.put(skuId + "",s);
    }

    @Override
    public void changeItemCount(Long skuId, Integer num) {
        BoundHashOperations<String, Object, Object> cartOps = getCartOps();
        CartItem cartItem = getCartItem(skuId);
        cartItem.setCount(num);
        String s = JSON.toJSONString(cartItem);
        cartOps.put(skuId + "",s);
    }

    @Override
    public void deleteItem(Long skuId) {
        BoundHashOperations<String, Object, Object> cartOps = getCartOps();
        cartOps.delete(skuId + "");
    }

    @Override
    public List<CartItem> getUserCartItems() {
        UserInfoTo userInfoTo = CartInterceptor.toThreadLocal.get();
        if(userInfoTo.getUserId() == null){
            return null;
        }else {
            List<CartItem> cartItems = getCartItems(CART_PREFIX + userInfoTo.getUserId());

            // 获取所有被选中的购物项
            List<CartItem> collect = cartItems.stream()
                    .filter(item -> item.getCheck())
                    .map(item -> {
                        R data = productFeignService.getPrice(item.getSkuId());
                        String price = (String) data.get("data");
                        // 更新为最新价格
                        item.setPrice(new BigDecimal(price));
                        return item;
                    })
                    .collect(Collectors.toList());
            return collect;
        }
    }

}
